Editor-in-chief, cryobiologist, and aging researcher Gregory M. Fahy and his associate editors Michael D. West, L. Stephen Cole and Steven B. Harris have compiled what might be the most impressive collection of articles on interventive gerontology to date in their 866 page collection The Future of Aging: Pathways to Human Life Extension. The book is divided into 2 parts. The first part includes general, scientific, social and philosophical perspectives on life extension. The second part is a collection of proposed interventions, which are organized in chronological order, starting with the (projected) earliest interventions first. Of course, such an organization of the materials necessitates a subjective estimation of when such technologies will be available and is bound to be controversial. The collection closes with a number of appendices about contemporary anti-aging funding and projects (SENS, Manhattan Beach Project).

I have read the book with the following two questions in mind:

1. Which approaches for increasing the maximum life span show clear near-term potential?

I cannot say that I am a big fan of Ray Kurzweil’s work. His general introduction to life extension, “Bridges to Life,” co-written with Terry Grossman, starts out on a restrained note, discussing the benefits of caloric restriction, exercise, basic supplementation, and predictive genomics. But it then ratchets up into bold claims about the future that rest on controversial premises: about biology and health following the same path as information technology; about the technical feasibility of molecular nanotechnology; and about the nature of mind. One thing that remains a mystery to me is how such an accelerating pace of anti-aging technologies could be validated considering the relatively long life expectancy of humans. Presumably we are expected to adopt a lot of these technologies based on their theoretical merits, success in animal studies, or short-term effects in humans.

Associate Editor Stephen Cole contributes a chapter on the ethical basis for using human embryonic stem cells. I suspect that his argument in favor of these therapies relies on adopting a definition of personhood that has more far-reaching, and more controversial, consequences than just permitting the use of human embryonic stem cells. One of the most disconcerting aspects of the bioethical debate on stem cell research is that many of its advocates seem to feel that if they do not see an ethical case against it, government funding for such research should be permitted. In essence, this means that opponents of embryonic stem cell research are obliged to financially support it as well. This is a recipe for further aggravating what has already become a passionate political debate.

As someone with relatively limited exposure to the biogerontology literature I should be cautious in singling out one technical contribution for high praise, but Joshua Mitteldorf’s chapter on the evolutionary origins of aging is one of the best and most inspiring articles in the field of aging research I have read and worth the hefty price of the book alone. Mitteldorf outlines a case for the theory that evolution has selected aging for its own sake and presents experimental findings that falsify other explanations for aging such as wear-and-tear and metabolic trade-offs. That aging is firmly under genetic control may appear the most pessimistic finding in terms of the prospects of halting aging but in fact allows for the manipulation of a number of selected upstream interventions that can inhibit or mitigate these programs.

It is clear from this ambitious book that cryobiologist Greg Fahy also has a strong interest in biogerontology but nothing prepared me for the encyclopedic knowledge that he displays in his lengthy chapter on the precedents for the biological control of aging. Fahy’s chapter further corroborates the view that aging is under genetic control. He also reviews a great number of beneficial mutations and interventions in animals and humans that can extend lifespan. Reading all these inspiring examples, however, I found myself faced with the same kind of despair as when reading about all the neuroprotective interventions in stroke and cardiac arrest. There is great uncertainty how such interventions would fare in humans (or other animals) and, more specific to the objective of human life extension, how we ourselves can ascertain that there are no long-term adverse consequences. Fahy does not run away from the most formidable challenge of all, rejuvenation of the brain without losing identity-critical information, but points out that identity-critical information might be retained despite the turnover and replacement of components that a meaningful life extension program for the brain would most likely require. Fortunately, people who make cryonics arrangements can feel a little better about this issue because their survival is not dependent on safe technologies becoming available in their lifetime.

Zheng Sui’s report on using high potency granulocytes to cure cancer in mice is one of the more exciting chapters in the book and a fine example of the role of chance discoveries in biomedical research (Zheng by accident discovered a mouse innately resistant to cancer). With substantial support of the Life Extension Foundation and other private donors, Sui is aggressively pursuing Leukocyte Infusion Therapy (LIFT) human trials instead of pursuing the torturous path of trying to illuminate the biochemical and molecular mechanisms that drive the successful results in mice. I should mention that a unique concern for cryonicists is that eliminating cancer in the absence of other effective anti-aging technologies could increase the likelihood of dying as result of identity-threatening insults such as cardio-vascular complications, ischemic stroke, or Alzheimer’s disease.

I must admit being somewhat disappointed in the chapter about “evolutionary nutrigenomics” by Michael Rose and his collaborators. Michael Rose has always struck me as one of the more level-headed and empirical aging researchers, and his work with fruit flies is a resounding demonstration of using evolutionary tools to investigate and combat aging. His short contribution to this book reads more as a quickly thrown together status update of their company, Genescient, than a rigorous treatment of the issues. Dispersed throughout the text are a number of interesting perspectives on alternative approaches to aging research and the validation of anti-aging interventions, but these issues are not discussed in much detail. Michael Rose’s work is of great interest, but this chapter is neither a good introduction to his work nor an in-depth treatment of the practical applications of his research.

Anthony Atala’s chapter, “Life Extension by Tissue and Organ Replacement,” is a fascinating update on the current status and potential of regenerative medicine and tissue engineering. Unlike most of the chapters in this book, the author reports a number of examples of successful clinical applications. It is a good example of how working with nature (instead of trying to improve upon it) can have meaningful near-term benefits. Unfortunately, there is no discussion of the progress in regenerative medicine for the brain. Obviously, such strategies cannot involve a simple replacement of the brain with a newly grown brain but selected repair technologies can play an important role in brain-damaging diseases and insults. The inclusion of “life extension” in the chapter title seems somewhat artificial to me because there is no distinct treatment about how tissue and organ replacement will be expected to contribute to life extension. Additionally, there is little discussion of contemporary artificial and mechanical alternatives to organs (or biological structural components) in this chapter, or in any other chapters in the book, which I think is a minor oversight.

Robert J. Shmookler Reis and Joan E. McEwen contribute a chapter about identifying genes that can extend longevity. Their discussion of the prospects for mammals includes the sobering observation that “many of the gains we can attain by a single mutation in the simpler organism may already have been incorporated in the course of achieving our present longevities.” Then again, unless aging is firmly under genetic control in simple organisms but the result of wear and tear in humans there should be (unique) approaches in humans that should confer similar benefits as well.

The publication of this book came to my attention when I learned about Robert Freitas’s contribution, “Comprehensive Nanorobotic Control of Human Morbidity (PDF),” so I was quite interested in reading this final chapter of the book. I am not qualified to comment on the technical aspects of his vision of nanotechnology. I think it is fair to say, though, that if resuscitation of cryonics patients is possible they will most likely be resuscitated in a future that has nanomedical capabilities resembling those that are outlined in this chapter. For this reason alone, this chapter should be of great interest to readers of this magazine. Of particular interest is the discussion of cell repair technologies and brain rejuvenation, a topic of great interest to cryonics. Freitas devotes considerable space discussing how anti-aging strategies like SENS can be achieved with medical nanorobots but the chapter falls short of offering a distinct exposition of a nanomedical approach to aging and rejuvenation. With such profound molecular capabilities one would think that such an approach would not just consist of updating existing biotechnological approaches to eliminate aging related damage with more powerful tools. I think that the distinct capabilities that molecular technologies have to offer would have benefitted from a more extensive discussion of their transformative capabilities. In particular, the section on nanorobot-medicated rejuvenation could have benefitted from a more rigorous treatment of the question of how these interventions would produce actual rejuvenation. Rejuvenation will be a practical requirement for most cryonics patients and it would be interesting to see a more detailed technical discussion of this topic.

Robert Freitas introduces the phrase NENS (Nanomedically Engineered Negligible Senescence) for his vision of how the goals of SENS can be achieved through nanomedicine. This raises an important question: is there any reason to believe that the timeline for “conventional” SENS will be different from the timeline for mature molecular medicine? It is hard to tell, but one could argue that the development of mature nanotechnology is more comprehensive than any strategies designed to deal with the causes or effects of the aging process. So why not just fund the work of biological and mechanical molecular nanotechnologists to accelerate meaningful re-design of the human organism? I think that the best answer is that our current state of knowledge does not justify giving a privileged position to any particular approach and having these visions of the future compete may be the best hope that we have for seeing meaningful rejuvenation and the resuscitation of cryonics patients in the future.

If there is one serious omission in this impressive collection of articles it is a more comprehensive chapter on the topic of biomarkers of aging in humans. As reiterated throughout this review, the gold standard and most rigorous determination of the efficacy of anti-aging therapies and interventions is to empirically determine whether they increase maximum human lifespan. For obvious reasons, most medical professionals and healthcare consumers are pressed to make decisions based on less rigorous criteria and the development of a set of reliable biomarkers of aging is highly desirable. Of course, the most rigorous case for successful biomarkers would require the same kind of long-term studies, leading to an infinite regress problem. How to break out of this predicament while retaining a framework to make rational decisions about life extension technologies is not a trivial problem and can be the topic of a whole new volume of articles. Interestingly enough, one of the most insightful perspectives on this issue is given in Appendix A by SENS researcher Michael Rae when he points out that therapies aimed at rejuvenation can be tested at much more rapid timescales than therapies to retard the aging process or increase the maximum lifespan.

Michael Rae also notes that SENS’s “engineering heuristic” is well established in other fields of biomedicine. It is certainly the case that aging research could benefit from a stronger emphasis on solving problems and repairing damage instead of completely trying to understand the underlying pathologies but it also needs to be pointed out that the engineering approach has not fared much better in areas of research that are notoriously resistant to effective solutions such as neuroprotection in stroke. Ultimately, the SENS approach cannot completely escape studying the mechanisms and metabolic pathways involved when treatments are compared and side-effects are studied. In this sense, the difference between SENS and alternative approaches is a matter of degree, not principle.

I think that the editors are justified in claiming that the prospects for solving the aging challenge have never looked better. A close inspection of all the chapters, however, shows that no significant interventions in the aging process in humans are available now, and I doubt they will become available in the near future. And even if the aging process can be eliminated, there will still be medical conditions and accidents that require placing a person in cryostasis until effective treatment is available. For the foreseeable future there is good reason to agree with Thomas Donaldson’s advice* that making cryonics arrangements is the most fundamental and sensible decision one can make in order to reap the benefits of powerful future life extension therapies.

Bertrand Russell once said that “most people would sooner die than think; in fact, they do so.” One does not need to look any further than the many responses to Kerry Howley’s recent article about cryonics and hostile partners in New York Times Magazine to find support for Russell’s witty remark. One commenter suggested that “an easy solution would be to just agree with him all the way to the grave. Then bury or cremate him. He’ll never know.” Such a cruel attitude may not be completely representative of what most people think about spousal disapproval of cryonics but it cannot be denied that some hostile partners and relatives have exactly responded in this way when faced with the legal death of a family member who had made cryonics arrangements. As a matter of fact, even indifference to a partner’s cryonics arrangements is a source of problems because the decreased sense of urgency, and a general unwillingness to assist with even the most basic cryonics first-aid procedures, produces substantial ischemic damage. Interfering with an individual’s cryonics wishes raises serious ethical questions because someone’s chance of survival has been reduced from a positive probability to zero.

Peggy Jackson, Robin Hanson’s wife, wonders “what’s so good about me that I’m going to live forever?” This is a strange presumption to make about life and death. Our culture generally does not have this presumption about moral worth and non-existence. As a general rule, we do not feel that someone has to justify her reason to seek medical care and try to remain alive. The argument is even less relevant in the case of cryonics because cryonics is not publicly funded. It is also a persistent misunderstanding that the objective of cryonics is immortality. It cannot be denied that some who have chosen to make cryonics arrangements have a desire for immortality but both major cryonics organizations simply present cryonics as an experimental medical procedure to treat terminally ill patients who cannot be sustained by contemporary medical technologies. As such, there is no credible rationale to depart from the presumption in favor of life that is implied in today’s medical practice. “What is so bad about me that I should not seek an experimental medical procedure like cryonics?” should be the obvious response when the presumption of death is made.

‘Choose life at any cost,’ ” Peggy says. “But I’ve seen people in pain. It’s not worth it.” We can agree that people should not choose life at any cost, but what is often ignored in discussions about cryonics is the rather obvious point that cryonics patients will not be resuscitated in the painful and debilitated state of a terminal patient but in a rejuvenated body without the disease the patient suffered from. Without such a condition for resuscitation, cryonics would be an exercise in futility.

One can only agree with bioethicist James Hughes that “there is a lot of ancient cultural stereotyping about the motives and moral character of people who pursue life extension”. In a number of posts on Overcoming Bias Robin Hanson himself has commented on the New York Times Magazine article. Robin draws an interesting parallel between the practice of Sati (“a funeral practice among some Hindu communities in which a recently widowed woman would either voluntarily or by use of force and coercion immolate herself on her husband’s funeral pyre) and objection to one’s partner’s cryonics arrangements.

Interestingly, Robin Hanson also seems to believe that a major source of anxiety about cryonics is fear of the future. Cryonics has “the problem of looking like you’re buying a one-way ticket to a foreign land.” Robin further thinks that a lot of the opposition to cryonics is driven by the possibility that it might actually work. After all, “If people were sure it wouldn’t work there’d be no point in talking about selfishness, immortality, etc. If the main issue were a waste of money we’d see an entirely different reaction.” This suggests that cryonics organizations could benefit from altering their public relations strategies. Less emphasis on discussing technical feasibility and more emphasis on dealing with anxiety issues.

The libertarian economist Bryan Caplan always gives cryonics serious consideration but sometimes has the habit of starting his discussion of the topic on a wrong note by discussing the most outlandish resuscitation scenarios instead of just focusing on the most basic form of cryonics; resuscitation of the same physical person that has been cryopreserved. Caplan seems to be quite interested in the question of what the odds of cryonics working are. Aside from the obvious rejoinder that the odds are much lower than they could be if cryonics was permitted as a pre-mortem elective medical procedure, the point needs to be reiterated that a small dedicated group of people can substantially increase these odds through scientific research and the creation of robust cryonics organizations. Cryonics is not just an issue of determining fixed probabilities but also about supporting the idea and participation to increase the odds of meaningful resuscitation of people who have been written off by today’s medicine.

Cryonics is decision making under certainty par excellence. If you cannot stomach any kind of uncertainty, cryonics is not the best decision for you. As the mathematician, and current Alcor patient, Thomas Donaldson has said: “There is an IRREDUCIBLE UNCERTAINTY which is basic to cryonics, not merely an adventitious consequence of our ignorance about how memory is stored.” In his article Neural Archeology Donaldson recommends that “if you’re involved in cryonics, you’ve got to make your peace with the unknown, because it will always be there. You’ve simply got to make your peace with it.”

The one silver lining of the recent discussion of partner hostilitily to cryonics is that there has been an increasing recognition of the need for financial and legal strategies to prevent catastrophic interference with one’s cryonics arrangements. Some of these strategies will be discussed in an upcoming issue of Alcor’s Cryonics Magazine.

There is a growing literature that discusses the technical aspects of revival of cryonics patients. The following list of the published literature was compiled by Ralph Merkle and Robert Freitas and published as an appendix of their article on molecular nanotechnology in Cryonics Magazine 2008-4:

Back in the late 1980’s, from Lake Tahoe, we published seven issues of short stories devoted to cryonics and where that might lead, primarily to uploading and a future now much like that envisioned in far more detail by Ray Kurzweil in his writings on the Singularity. The early issues were mainly about the emotions of those deciding on cryonics and trying to get themselves frozen, while the later issues delved into everything from nanobot warfare and gray-goo meltdown dangers to Albert Einstein unexpectedly going “self-conscious” and emulated as a powerful entity, in connection with an entertainment virtual reality endeavor. There are three stories by Thomas Donaldson that are quite poetic about the far future, and two by Lee Corbin, which stretch the imagination to the point of envisioning a present-day intellect being able to experience the heat death of the universe, but there are just as many stories which deal with very basic human emotions about cryonics.

Full access to all of this is on our basic LifeQuest Index Page. At the bottom you’ll find links to the Amazon.Com pages, where the republished stories are available on Kindle as well as in hard copy. If you take the ‘author link’ a little way down the main Amazon.Com page, you’ll see a blog where just this morning an entry was made for a new story, “The Box”, online in Power Point downloadable as PDF. For any who might wish to have a brief glance, here’s the LINK for that.

Hope you enjoy these stories; they’re available on line, so it’s not necessary to buy a copy on Amazon. On the other hand, if you have a reluctant relative or friend you want to try to bring over to your way of thinking, the hard copy version might be helpful.

The cryonics organizations Alcor and the Cryonics Institute have taken great care to correct some of the persistent myths about cryonics. With so much widespread misinformation being circulated in the media it seems trivial to pay attention to some of the misconceptions that some people who are sympathetic to cryonics hold. But the price of ignoring these opinions is that progress in the science of cryobiology and practice of human cryopreservation is adversely affected. What follows is a list of 5 “dangerous” ideas (or misconceptions) about cryonics and their consequences.

1. First in, last out.

A popular expression in cryonics is that the first person who was cryopreserved will require the most extensive repair technologies and therefore will be the last person to be resuscitated. The underlying assumption in this view is quite reasonable: when advances in cryopreservation technologies are made, demands on advanced future repair technologies will be lessened. The problem with this view, however, is that it assumes that advances in cryobiology and neuroprotection are the only factor influencing the quality of care in cryonics. Unfortunately, advances in the science of cryopreservation will not automatically translate into better patient care. Other factors, such as the delay between time of “death” and start of procedures, and the protocols, equipment and personnel of the responding cryonics organizations, matter as well. For example, if a cryonics standby team is not able to get to a patient before 24 hours after cardiac arrest, pumps him full of air during remote blood washout, and ships him back to the cryonics organization at subzero temperatures, that patient will not benefit from advances in human cryopreservation such as rapid induction of hypothermia, neuroprotection and vitrification.

A professional cryonics organization with “old” technologies may on average do better than an incompetent cryonics organization with “new” technologies. The important lesson to be drawn here is that the concept of “patient care” is a meaningful concept in cryonics and consumers of cryonics services need to evaluate their cryonics providers on their ability to provide good care.

2. Only the future will tell us how good our cryonics procedures are.

It is true that only the future will tell us whether cryonics patients will be resuscitated or not; but that does not mean that we cannot say anything meaningful about the quality of care in individual cryonics cases. The most obvious point is that we can compare actual patient care to the published protocols and objectives of the cryonics organization. More specific observations can be made during a cryonics case using medical equipment. In a well-run cryonics case a number of physiological and chemical measurements are made to determine the response of a patient to various interventions. As a general rule, the objective of cryonics stabilization procedures is to keep the brain of the patient viable by contemporary medical criteria. The danger of thinking of cryonics as one single experimental procedure that can only be evaluated in the future is that it ignores the fact that actual cryonics procedures consist of various separate procedures that can be monitored and evaluated using existing medical tools. The least that a cryonics consumer should expect from his cryonics organization is that it discloses its cryonics procedures to the general public and produces detailed case reports.

3. Cryonics patients are no longer being frozen.

Because not all cryonics patients will be “ideal” cases, this view is vulnerable to the same objections as the “first in, last out” rule, but there are some other issues that are important to mention in this context. The most important fact to be stressed is that ice formation is not a binary all or nothing thing but a continuum ranging from straight freezing (cryopreservation without cryoprotection) to complete elimination of ice formation. Although there have been many cases where patients have been frozen without the use of a cryoprotective agent, its opposite, complete vitrification, should be considered a theoretical ideal. The degree of ice formation is determined by the nature and concentration of the cryoprotective agent. For example, low concentrations of the cryoprotectant glycerol will result in more ice formation than higher concentrations of glycerol.

What has changed in the recent years is that both major cryonics organizations are now offering cryopreservation using vitrification agents. Although these vitrification agents are formulated to eliminate ice formation, it is generally believed that such a result is not achievable in all tissues and organs in the human body at the moment. Another important point to be made is that not all solutions that can eliminate ice formation are equal because they can differ greatly in toxicity. The technical challenge in cryonics is not so much to eliminate ice formation but to develop vitrification solutions with no or limited toxicity. Although it is correct that contemporary vitrification solutions can solidify without ice formation, delays in response time, poor patient care, and high toxicity can offset most of these advances.

4. The probability that cryonics will work is X.

Both critics and supporters have made specific probability estimates about how likely cryonics is to work. In its worst form such probability assessments convey nothing more than putting a number on overall feelings of pessimism or optimism. More serious attempts have been made to calculate a specific probability that cryonics will work. Such attempts usually go as follows: A number of independent conditions (or events) for cryonics to work are distinguished, these conditions are “assigned” a probability, and the total (or joint) probability is calculated by multiplying them. Although such calculations give the semblance of objectivity, they are equally vulnerable to the fundamental objection that assigning one single number to the probability that cryonics will work is just a lot of hand waving. How many independent events are there and how do we know that they are independent? What is the basis for assigning specific probabilities to these conditions? What are the effects of minor changes in the numbers?

Probability calculations are not completely useless. They can help us in identifying important conditions that need to be satisfied for resuscitation. They can also help identify weak links that can be improved. But probability estimates can be dangerous as well when we take them too seriously and discourage people from making cryonics arrangements. The point here is not that we should refrain from being skeptical but that if we make quantitative estimates we should be able to back up our statements with rigorous arguments or just confine ourselves to more qualitative statements. Another objection to making cryonics probability estimates was made by the cryonics activist and mathematician Thomas Donaldson. He makes the common sense point that many of these conditions are not independent of what we do. We can make a contribution to increasing the probability that cryonics will work.

Last but not least, what does it mean when we talk about “cryonics working?” It is conceivable that cryonics will work for one person but not for another, reflecting improved technologies and protocols. Perhaps asking the question if cryonics patients can be “revived” is the wrong question. As the cryobiologist Brian Wowk has pointed out, the real question is how much original personality would survive the many possible damage/repair scenarios, not revival per se. Survival in medicine is not a simple black-and-white issue, as evidenced by people who recover from stroke or cardiac arrest but with personality and memory alterations. And it is worth mentioning once more that how much of our personality survives is depended on what we do to improve the quality and long-term survival of our cryonics organizations.

5. I will sign up for cryonics when I need it.

It should be obvious without much reflection why this is a dangerous idea. At the time a person really needs cryonics, he may no longer be able to communicate those desires, lack funding to make arrangements, or encounter hostile relatives. A more subtle variant concerns the person who expects that aging will be solved before cryonics will be necessary. This person may or may not be right, but such optimism may not make him more immune to accidents than other people. This mindset is often observed among young “transhumanists” and practicing life extensionists. A related, but rarer, variant is to postpone making cryonics arrangements until the cryonics organization makes a number of changes including, but not limited to, hiring medical professionals, stop wasting money, becoming more transparent, giving members the right to vote, etc. Such issues are important, and need to be addressed, but a safer response would be to join the organization and influence its policies, or, if this will be necessary, combine with others to start a competing cryonics organization without such flaws.

There are not many people who think that it is sensible to make cryonics arrangements, but there are even fewer people who have actually made such arrangements.

As we have seen, some of these dangerous ideas share the same or related assumptions and produce identical effects: decreased scrutiny of cryonics organizations and a decreased chance of personal survival. An important common theme is that cryonics cannot be treated as one single monolithic technology and that the fate of our survival depends as much on the state of the art in human cryopreservation technologies as on the competence of cryonics providers. Caveat emptor!

Just a superficial look at the history of the life extension movement will suffice to show the rise and fall of numerous fads and trends in ideas about the mechanisms and “treatment” of aging. Psychological meliorism and simplistic visions of biochemistry create overly optimistic expectations about extending the maximum human lifespan. But how can we know if a treatment is able to extend the maximum lifespan of humans without giving it to them and waiting….

The best possible proof that a treatment will indefinitely prolong the lives of human beings must come from a demonstration of its effects on human beings. Not fruit flies, worms, mice, or rats, but human beings. Yet there’s a small problem here: we are human beings ourselves, and a proof that a treatment prolongs the lifespan of people will take … at least the lifespan of some people…cryobiology can progress much faster than antiaging. Not only that, but its progress almost totally lacks the problems of proving that an advance has happened. The state of a brain, or even a section of brain, after vitrification and rewarming to normal temperature, shows directly whether or not the method used improved on previous methods.

What about treatments that have been shown to extend the maximum lifespan in small mammals? Or using treatments that have been shown in humans to stop or slow down the aging process?

“It takes a long time and the actual reports on clinical use of a drug for physicians to get an idea of the effects of longterm use of that drug. Very few drugs of any kind get formal tests for the entire lifespan of normal people taking them.”

Even if people are not prevented from experimenting with various life extension technologies, these epistemological and practical problems cannot easily be overcome.

“No matter what some scientists say, a cure for aging involves many problems all of which will need time for their solution. Even now, you may be young and feel that you need not think about cryonics because some means to slow your aging will come before you’ve gotten very old, and from that still other means to slow your aging even more … and so to true agelessness. In this article we have seen why such dreams of a rapid solution to aging cannot come fast for any of us. At the same time, cryonic suspension able at least to preserve our brains in a reversible form, allowing restoration of vital functions, looks likely to come much sooner.”

And as Robert Prehoda pointed out in an old interview, successful treatment of aging will still leave an individual vulnerable to accidents:

Immortality is statistically impossible because accidents would eventually eliminate all individuals in any non-aging population.

Despite these arguments, the life extension and “transhumanist” movement remains many times larger than the people who have made cryonics arrangements. Some reasons for this are explored in another entry, but the mystery remains.

But as Brian points out, the key idea of cryonics is that patients should continue to be cared for, even if contemporary technologies cannot reverse cryopreservation. As has been reiterated on this blog before, even when suspended animation is perfected, there still will be a need for cryonics to care for patients that cannot be treated by contemporary medical technologies. Dismissing cryonics until there is proof of successful suspended animation ignores the fundamental, and humane, premise of cryonics to use low temperature biostasis so that critically ill people may benefit from medical technologies that have not yet arrived.

Suspended animation is not cryonics. The paradigm shift of cryonics is something different. It is a paradigm shift that could happen before suspended animation is perfected, or perhaps not even after suspended animation is perfected. The key idea of cryonics– the paradigm shift of cryonics –is the idea that patients should continue to be cared for even if they are beyond recovery by contemporary means. It’s the idea that almost everything that medicine calls “death” in a particular era is destined to become a treatable pathology in a later era. That is an idea that transcends suspended animation, and that is so far from normal social mores that it may never be accepted by the mainstream whether there is suspended animation or not. It is a paradigm shift that requires overturning the idea of closure, which is a deeply uncomfortable proposition for most people regardless of demonstrated technology.

…

When people say that they hope they never need cryonics, I’m not sure in what sense they mean this. Do they mean that in the same sense that we all hope we never have to go to a hospital, even though the probability of eventually being hospitalized for some reason converges to near certainty? Or do they actually believe that they may never need cryonics? Such a belief is equivalent to the belief that one will never suffer a medical crisis that is untreatable by available medicine. I suppose an alternative possibility is the belief that one’s first and last major medical crisis will be vaporization. That doesn’t seem very likely. We live in a time when for the foreseeable future, Singularity or not, virtually everybody is going to need some form of cryonics at some time.